bromine in tetrachloromethane 2 h; Ambient temperature;

1: 1.) conc. HCl, 2.) ZnCl2, HCl / 2.) ether, CH2Cl2, 20 deg C, 2 h 2: 65 percent / Br2 / CCl4 / 2 h / Ambient temperature View Scheme

1: 1.) conc. HCl, 2.) ZnCl2, ZnO / 2.) ether, CH2Cl2, -20 deg C, 4 h 2: ZnCl2, HCl / diethyl ether / 20 °C 3: 65 percent / Br2 / CCl4 / 2 h / Ambient temperature View Scheme

1: ZnCl2, HCl / diethyl ether / 20 °C 2: 65 percent / Br2 / CCl4 / 2 h / Ambient temperature View Scheme